While I enjoy going into some things unspoiled if I'm not super invested (the last Twilight movie comes to mind), I often spoil myself silly going into things I'm really excited about (say, The Avengers). But it's usually fine because I still enjoy actually seeing it for myself.

When the spoiler is bad news for something I'm really invested in, though, I must say: THAT can ruin things for me. I dreaded going into the last episode of Battlestar Galactica and the last book of The Hunger Games trilogy. Yet I still can't regret getting that knowledge beforehand--at least I was prepared.

So I guess for me a spoiler itself can't make or break an experience for me. The content of the spoiler can, but that's due to the content itself rather than any advance knowledge of it.

I actually don't mind spoilers that much, given that I have a tendency myself to peek at the end of a book. I don't mind much spoilers when it comes to movies either _ except when they prevent me from appreciating a particularly unexpected twist in the scenario. For instance, you really can't appreciate Usual Suspects if you are told who is Kaizer Soze ; or Fight Club if you already know Tyler Durden isn't who he seems to be ; or even the first Saw movie if you already know who and where is Jigsway all along!